Batteries

Might also depend on what brands that battery store sells. And how much granularity in their battery tracking system (brand and type? or just type? or...?). Apparently, there are AGMs... and then there are good AGMs...

I think that'd be my first guess, too. Second guess might be they weren't sufficiently recharged after each cycle...

Or maybe some combination of stuff like that...

-Chris

It could be a charger issue. The Lifeline warranty is 5 yr. with proration from 3 to 5 year. No doubt they are a top quality battery. I look at longevity vs cost and have not seen where AGM's outlast wet cell if properly maintained. Just priced AC Delco 8d wet cell @ $190 each x 10 = $1900. Lifeline 8D @ $750 x 10 =$7500. Plus labor on both. I guess my question would be "will they last 3 times longer"? I do understand that many do not maintain wet cells properly(if at all) and in that case a maintenance free battery would be the best choice. Also, a charger issue can kill your batteries at any time. Just saying it is hard to justify the difference in cost with all the possibilities of short battery life. Most boats I have owned needed batteries and/or chargers replaced.

I also agree with you with that price comparison for AGM maintenance free. Not much of a premium to pay. I was comparing the existing Lifelines to wet cell which was a no go. Thanks for that info, have not shopped the different AGM's yet.

I agree with you there and that's why I still use the lead acid batteries. I also don't understand worrying about acid spill. If the batteries are not over filled you'd need some serious pitch and roll angles for the acid to come out of the batteries. Sure they will gas a bit when charging but is that really an issue if it's in a ventilated engine room? Take a wet battery at proper level and look at how much you need to tilt the battery before the acid comes out, at that point you got bigger problems because the coast guard is on it's way

I have a bank for four group 31 lead acid used for the house I bought at napa for 100 bucks each. Deka makes the deep cycle group 31 batteries for napa so it's the same battery just less $$.
They are now going on 7 years of discharging to 50% every weekend (just about) during season (about 7 months - I'm in the north east) and still have plenty of life left.

I water them once a year at the end of the season and they don't really need to be watered.

It's all in the float voltage of the charger. If the float voltage is too high (typically 13.3v for lead acid) it'll cause gassing and you'll be adding water more often. If the voltage is too low, I think < 12.8v you'll start to get sulfation on the plates and they will loose capacity.

Reading suggests AGMs can be easily killed, too, apparently by lack of sufficient recharging after a discharge cycle.

In that case, I think I'd not consider them "maintenance free" -- just the "maintenance" (expeditious recharging to 100%) is different compared to wet batteries.

-Chris

I am still looking for those $250 8D AGM's.

I wanted your source! lol

I purchased two 8Ds from BATTERIES PLUS for $182.00 each and two from INTERSTATE for $340.00 each. The BATTERIES PLUS 8Ds are going strong after 5 years. Had to replace the INTERSTATEs after 3.5 years. All were lead acid. Moral....costs matter as there are only 5 manufactures in the US

A big, solid 8D is fine if cared for. Abuse it and it won't like it at all. Jeez, the number we had to change due to lack of water/sulfured plates/bent plates. Look after them and they last well. Never buy the cheapest as the quality really is poor, good ones last.

We are agents for the Odyssey range of batteries. Talk about longevity! A 40ft container of them was sent to the huge Afghanistan Forces base. They sat, kinda forgotten, for 14 years lost in the vast debris of gear. On their return to the US for testing, the only ones that showed signs of a lower performance was where the forklift truck had ran through the middle of them!

Your Tax Dollar being shown it's usual respect our military.

http://www.odysseybattery.com/

One thing I've found is that wet cell batteries with a watering system will well outlast Agm.

Good to know, It is hard to justify AGM's. Especially on boats with 8 or more 8d's. The difference in cost would buy a lot of diesel fuel and maintenance.

Good point. How about a small house bank with two gens?

FWIW, our oldest bank of Odyssey batteries (3x G31 PC-2150s) is just now going into its 12th season.

They have suited the way we use the boat, and maintenance on wet batteries wouldn't have been easy... so the higher cost is a wash, for us.

Due for replacement sometime this Summer, though. Think I've gotten my money's worth.

-Chris